This recent tip showed how to disable the backup process when syncing an iPhone by using a Terminal command. The way I do it is much less elegant, but has the benefit of being simple for novices and allowing the user to choose whether to perform a full back-up or a simple sync when the phone is plugged in.

I've created an album in iPhoto called iPhone Sync which contains one photo. When I plug in my phone (which is set to not auto-sync on connect), I can perform the lengthy backup by pressing the Sync button in iTunes.

If I only want to perform a basic sync (which will copy any new music, videos, or applications to the phone), however, all I have to do is toggle that album in the Photos tab of the iPhone in iTunes. This adds an Apply button where Sync used to be. Clicking the Apply button avoids a full back up, and only copies over new files.

[robg adds: Another advantage of this method over canceling a backup that has started is that it will leave your existing backup intact. The combination of iTunes 7.7.1 and iPhone firmware 2.0.1 has mostly solved my lengthy backup problems -- they're down to a more-reasonable five-ish minutes or so.]

[robg adds: Another advantage of this method over canceling a backup that has started is that it will leave your existing backup intact. The combination of iTunes 7.7.1 and iPhone firmware 2.0.1 has mostly solved my lengthy backup problems -- they're down to a more-reasonable five-ish minutes or so.]

The overriding warning, though, is that canceling a backup will corrupt it, and leave you without a usable backup.

The combination of iTunes 7.7.1 and iPhone firmware 2.0.1 has mostly solved my lengthy backup problems -- they're down to a more-reasonable five-ish minutes or so.

Hasn't helped for me at all. I tried to sync my phone today and the backup got about halfway through in 2 hours or so before the cat decided to step on the power button of my iBook and turn it off (I was in the other room or I'd have stopped her).

Well, my backup last night required nearly five hours. I'm afraid, till at least bedtime later today, to attempt a repeat performance. What is even more scary are reports that individuals with presumably uncorrupted backups are still finding them unusable when they need to resort to a restore.

This tip seems a reasonable work around for now, although I am personally making use of the backup disabler application noted in the comments above just to be sure.